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Precise torque control for interior mounted permanent magnet synchronous motors with recursive least squares algorithm based parameter estimations
Get PDFInterior mounted permanent magnet (IPM) machines have superior features comparing to their counterparts for electric vehicle traction applications. Having relatively higher efficiency, high torque and power densities, low torque ripple and not requirement of regular maintenance are among their superior features. It is widely known that the precise torque control in practical IPM drives highly relies on accurate knowledge of machine parameters viz, inductance values and magnetic flux linkage. These machine parameters vary significantly in real time operation depending on manufacturing tolerance, operating temperature, inductance saturation, load torque and so on. It is known that d-and q-axis inductances and magnetic flux linkage at the full load operation may be approximately 20%, 35% and 20%, respectively, lower than their actual values at no-load operation. It is also commonly known in the literature for traction applications that these variations (considering wide range operation) have much influence on both drive system efficiency and output torque production compared to other system nonlinearities such as stator resistance variation. It has been achieved in this paper that these parameters are estimated online with fairly high accuracies of each, utilizing recursive least squares (RLS) algorithm. The superiority of the proposed drive achieving considerably higher output torque (-28,7% of peak torque) is validated through extensive realistic simulations with nonlinear machine model of a 4.1 kW prototype IPM machine designed and manufactured for traction applications. Proposed strategy and its superiority among state-of-art drives are discussed in detail. (c) 2021 Karabuk University. Publishing services by Elsevier B.V
A New Type Of Contractıon Vıa Measure Of Non-Compactness Wıth An Applıcatıon To Volterra Integral Equatıon
Get PDFDarbo fixed point theorem is a powerful tool which is used in many fields in mathemati s. Be ause of this feature, many generalizations of this theorem and its relations with other subjects have been investigated. Here we introduce a generalization of an F-contration of Darbo type mapping and define a new contration by using both function classes and uniformly convergent sequences of functions and examine some of its properties. Afterward, we show that the new type of contration, which we all F-Darbo type contration, has more general results than many already studied in the literature. Further-more, we explain the results of F-Darbo type contration mapping with an interesting example. Finally, we give an application to solve the Volterra-type integral equation with the new type contration. © 2022. Publications de l''Institut Mathematique. All Rights Reserved
Chiari I malformation presenting with ganglion cell complex thinning on routine examination
Get PDFChiari I malformation (CMI) is a rare congenital disorder characterized by the caudal displacement of cerebellar tonsils through the foramen magnum into the cervical canal(1). Ophthalmological signs include retro-orbital pain, diplopia, photophobia, impaired visual acuity, nystagmus, strabismus, and papilledema(2-4). The diagnosis is mostly based on magnetic resonance imaging (MRI) findings © This content is licensed under a Creative Commons Attributions 4.0 International License
Effects of the COVID-19 Pandemic on Bladder Cancer Diagnosis and Treatment Processes; A Turkish Multicenter Study
Get PDFObjective: The coronavirus disease-2019 (COVID-19) pandemic effect diagnosis and treatment of certain conditions, including bladder cancer (BC). This study aimed to evaluate the effects of the COVID-19 pandemic on BC diagnosis and treatment.Materials and Methods: Following the approval of the ethics committee for the study, data of 869 patients who underwent surgery for BC in the 2-year period between March 1, 2019 and February 28, 2021 were analyzed retrospectively. The number of surgeries performed for BC, the time elapsed between symptoms and diagnosis, the treatments performed, and the operative pathologies were compared before and during the COVID-19 pandemic.Results: During the COVID-19 period, there was a decrease in the total number of BC surgeries compared to the pre-COVID-19 period (p=0.004). It was observed that this decrease was due to a decrease in patients newly diagnosed with BC (p=0.001) as well as the decrease in the number of primary transurethral resection for bladder tumor procedures performed. There was no difference in the tumor stages of the patients at diagnosis (p=0.9). Intracavitary Bacillus Calmette-Guerin therapy use in high-risk non-muscle invasive bladder cancers (NMIBC) patients also decreased (p=0.008) during the pandemic period. It was observed that the time between symptom and diagnosis was longer in MIBC than in NIMBC during both periods (p<0.001).Conclusion: Diagnosis and treatment of BC have been adversely affected by the ongoing COVID-19 pandemic. The decrease in the number of new diagnoses may not reflect a true decrease in BC incidence, meaning that BC cases that arose during the pandemic are likely to be diagnosed at a more advanced stage
Evaluation of resistance of Turkish bread wheat (Triticum aestivum) varieties to recently emerged Puccinia striiformis f. sp. tritici races
Get PDFUsing genetic diversity has made significant contribution to stripe rust resistance to improve wheat production. However, rapid evolution of the Puccinia striiformis f. sp. tritici (Pst), and emergence of virulent races can negatively affect the wheat genotypes with race-specific resistance gene(s). In this study, reactions of 130 bread wheat varieties, released from 1931 to 2014, were evaluated to recently emerged Pst races in Turkey, PSTr-6 and PSTr-23, at seedling and adult-plant stages. 65.4% and 67.7% of wheat varieties showed susceptible reaction to PSTr-6 and PSTr-23 at seedling stage, respectively. Moreover, coefficient of infection (CI) values generated by infection type (IT) and disease severity (DS) data demonstrated that PSTr-23 (59.78) was more virulent than PSTr-6 (57.93) at adult-plant stage. In addition to these, the presence of important yellow rust (Yr) genes in these varieties was investigated at molecular level. It was determined that the frequencies of three Yr genes, Yr5, Yr10 and Yr15, among these varieties were 1.5, 6.2 and 3.8%, respectively. However, none of them had Yr36 and only one variety had Yr5+Yr10 combination with frequency of 0.7%. In conclusion, most varieties have not these Yr genes and possess a moderately resistance/susceptible reaction to both races in general. © 2022 Elsevier Lt
Humidification Devices
No full textDry and cold medical gases administered during noninvasive ventilation (NIV) may cause anatomical and physiological disorders in the upper airways. The resulting symptoms may impair patients' compliance with NIV and cause unwanted complications. Various parameters such as inspiratory flow and air leaks during NIV may have a negative effect on humidification. Humidification can affect patient comfort and breathing work, especially during prolonged NIV treatments. The devices used to humidify and heat inhaled gases are heat and moisture exchangers (HME) and heated humidifiers (HH). © 2022 by Nova Science Publishers, Inc. All rights reserved
Global Developments in Climate Policy and Migration Policy: Can the UN Be a Base to Create an Adequate Legal Framework?
No full textThis commentary discusses how the latest resolution adopted by the UN Human Rights Council (UNHRC), recognizing "The Human Right to a Safe, Clean, Healthy and Sustainable Environment," paves the way for a juridico-political argument over Climate-induced problems. First and foremost in this piece, the climate change-related refugee movement is examined from a critical perspective. Additionally, the paper also asserts that the issue of "climate refugees" is neglected, and climate-induced migration challenges the current international migration framework. Therefore, this commentary seeks to investigate the impacts and relevance of international law and politics on "climate refugees" in the case of the Republic of Haiti. Lastly, the paper offers practical solutions for those displaced by environmental factors
Placental and Umbilical Cord Blood Oxidative Stress Level and Telomere Homeostasis in Early Onset Severe Preeclampsia
No full textObjective Although the etiopathogenesis of preeclampsia (PE) is unknown, evidence suggests that it may be associated with increased oxidative stress. Studies have shown that oxidative stress can affect DNA fragments called telomeres. However, the interactions of PE, oxidative stress, and telomere length are not clearly known. This study aims to evaluate the oxidative/anti-oxidative stress balance in the placenta and umbilical cord and examine the effect of oxidative stress on telomeres. Materials-Method Cord blood and placental samples were collected from 27 pregnant women with severe PE (28 0/7-33 6/7gestational weeks) and 53 healthy pregnant women. Telomere length (TL) was measured by real-time PCR in the cord blood and placenta tissue. Total antioxidant status (TAS) and total oxidant status (TOS) levels were measured in the cord blood and placenta tissue using a colorimetric method. Results No significant differences were found between groups regarding age, BMI, gravida, parity, and newborn gender (p>0.05). Cord blood and placental TL of PE patients were significantly shorter than the control group, while cord blood and placental TAS and TOS levels were higher (p<0.05). The results of a multivariate logistic regression analysis showed that the level of placental TOS in PE patients (OR=1.212, 95% CI=1.068-1.375) was an independent risk factor affecting PE. Conclusion This study found that oxidative stress is an independent risk factor in the development of PE and shortens TL in both placental and umbilical cord blood. Future research on telomere homeostasis may offer a new perspective for the treatment of PE. © 2022 Georg Thieme Verlag. All rights reserved
Density functional theory investigation on structural, mechanical, electronic and vibrational properties of Heusler alloys AlXIr2 (X = Co, Cr, Cu, Fe and Zn)
Get PDFThis study focuses on the detailed investigation of full-Heusler AlXIr2 (X = Co, Cr, Cu, Fe and Zn) alloys. A first -principal plane-wave pseudopotential method based on density functional theory is adopted. The quantum -espresso package combined with the generalized gradient approach is used to reveal the structural, electronic, magnetic, mechanical and lattice dynamic properties of full-Heusler AlXIr2 (X = Co, Cr, Cu, Fe and Zn) alloys. The elastic constants are used to determine elastic stabilities of alloys based on Born criteria. The analysis showed that all alloys are elastically stable. Further detailed analysis has been carried out to reveal mechanical properties. It is found that all alloys are ductile and anisotropic. The electronic band structures are also obtained. All alloys except for AlCrIr2 are found to be metallic. AlCrIr2 has half-metallic nature. In addition, AlCrIr2, AlFeIr2 and AlCoIr2 has shown magnetic properties. The phonon spectra and density of states are investigated to examine dynamical stability. It is seen that all alloys exhibit dynamical stability due to having positive phonon frequencies
Measures and Gap Analysis on the Impact of NonIndigenous Species on the Black Sea Ecosystem
Get PDFOverseas transportation of non-indigenous species (NIS) and their permanent habitation of secondary regions pose a critical threat that adversely affects the marine environment and marine based economic activities and applications. The transportation of NIS causes a decline in fish industries, spoilage of culture fishing stocks, rising production costs, adverse effects on human health and changes in biological diversity. The most prominent alien species in Turkish Black Sea waters are species invasions which are witnessed in the Black Sea. The Black Sea, which has incurred significant losses in biodiversity due to the increasing eutrophication and various pollution related problems, have surfaced significantly and provided a considerably suitable environment to invasive NIS. In this study, measures and legal gaps are evaluated to reduce and control the entry and spread of NIS into the marine environment